Lights, Camera, Reaction!

Unit Summary

First-year chemistry students learn the basics of chemical reactions, and then dig deeper to produce unique multimedia demonstrations that will be used in an educational instructional video for a cable channel. Online simulations and microscaled investigations allow students to study many reactions safely in a short period of time. Small groups of students are assigned one of five basic chemical changes (synthesis, decomposition, single displacement, double displacement, or combustion) for further investigation. After careful consideration, each student selects one reaction and demonstration that best illustrates the particular reaction, and develops a slideshow presentation that can be used in the final class video. As a final assessment, students are given a unique "recipe" for a set of reactants, and they are asked to identify the reaction type and the products that are likely to result.

Curriculum-Framing Questions

Essential Question
What causes change?

Unit Questions
How do patterns allow us to predict chemical reactions and their products?
How do chemical reactions affect everyday life?

Content Questions
What is a chemical reaction?
How does chemical change occur?
How can you tell if a change is chemical or physical?

Assessment Processes

View how a variety of student-centered assessments are used in the Lights, Camera, Reaction! Unit Plan. These assessments help students and teachers set goals; monitor student progress; provide feedback; assess thinking, processes, performances, and products; and reflect on learning throughout the learning cycle.

Instructional Procedures

Prior to Instruction
Send the Using Projects brochure home to introduce parents to the projects students will complete during the upcoming year.

Session 1: Assess Prior KnowledgeIntroduce the project with the Essential Question, What causes change? Prepare a slideshow of various pictures that demonstrate physical change (such as fall colors, volcanoes erupting, fireworks, landfills, and so forth). Have students share evidence that change has taken place in the pictures. Lead the discussion so that students discern chemical changes versus physical changes.

Navigate to Chemical Reactions*, an Online Labs simulation that allows students to carry out a number of different reactions and classify them as chemical or physical changes. You may wish to review the animation as a whole-group activity and answer any questions before students enter the simulator. As students complete the online investigations, ask them to record their thoughts and explanations for what they see taking place. Use the following questions to prompt further thinking:

What is required for a chemical reaction to take place?

Why does chemical change occur?

How can you tell if a change is chemical or physical?

Following the online simulation, ask students to complete the associated online quiz* to check for understanding.

Session 2: Foundation KnowledgeExplain the fundamental features of chemical change, and describe how it differs from physical change. Use the many online videos, virtual simulations, and slideshows listed in the resources section to deliver instruction on the five types of chemical reactions (synthesis, decomposition, single displacement, double displacement, and combustion) and the six signs that suggest chemical reactions have occurred (emission or absorption of heat, emission of light, formation of a solid, formation of a gas, color change, and odor).

Explain that in its most basic sense, a chemical reaction is an event in which atoms rearrange themselves and bind together in new ways. Sometimes, this involves a single substance, such as when three oxygen molecules rearrange their atoms to form two ozone molecules, or 2 O3, or it can involve two or more substances, such as when an acid and a base combine to form salt and water as follows:

HCl + NaOH --> NaCl + H2O

Explain that chemical reactions can either take in or give out energy when the atoms rearrange themselves. When oxygen is converted to ozone, it takes in the energy supplied by sunlight. When an acid reacts with a base resulting in salt and water, it gives out energy as heat. A reaction that takes in energy is endothermic, and a reaction that gives out energy is exothermic.

Session 3: Explore
Set up stations in the classroom in which students complete a microscale investigation on each type of chemical reaction. Investigations and how to set them up can be found online at the University of Nebraska-Lincoln* Web site. Post reaction types, instructions, and safety guidelines. After students have completed each station, have students complete a summary for each investigation. Use the responses to the summary questions to gauge their understanding of chemical reactions. Discuss the Content and Unit Questions, How can you tell if a change is chemical or physical? and How do patterns allow us to predict chemical reactions and their products?

Another option is to use virtual simulations instead of setting up physical investigations. This option is especially viable if you are limited by time or equipment. Set up the following simulations:

Post reaction types and instructions next to each computer. After each station, have students complete the online quiz associated with each investigation and write a brief summary of their learning. Use their responses to gauge understanding of chemical reactions.

Session 4: Equations
Teach students about equations. Equations show:

Reactants that enter into a reaction

Products formed by the reaction

Amounts of each substance used

Each substance produced by the reaction

Navigate to Balancing Chemical Equations*, a PhET simulation that encourages students to experiment with making changes to balance chemical equations. Demonstrate how to navigate the simulation controls, then allow students ample time for investigation and practice.

Optional extension activity: Allow time for students to learn more and practice their skills by interpreting, writing, and balancing equations in tutorials at SciLink NSTA*. Have students do their work in their science journals and check their journals frequently to assess their understanding.

Session 5: Lights, Camera…
Introduce the scenario that a local cable channel would like to hire a group to produce an educational instructional video to air during National Chemistry Week (October). Explain that each group is assigned one of the reaction types. Each group then produces a digital product (for example, a wiki, video, animation, podcast, or student slideshow) that is informative and keeps the attention of the audience. Assign advanced students to be “directors” and “producers” to compile all the group projects onto one DVD or class website. Divide students into groups and assign one reaction type to each group (if the class is large, assign reaction types to more than one group). Using print and electronic sources, students study one reaction type and answer the following questions:

Sessions 6 Through 9: Look Deeper
Have student groups research an everyday example of their type of chemical reaction and prepare a demonstration or experiment on the topic. Encourage students to explore topics that are relevant to their lives and impact society in some way (such as waste management, fireworks, and so forth). Students can use the University of Nebraska-Lincoln* Web site for interesting and safe microscaled examples of reaction types. Another option is to use Online Labs* and PhET Simulations* as an alternative to performing actual experiments. After students deliberate about which example best illustrates a reaction type, have them submit a proposal that includes the following:

Description of the microscale demonstration

Rationale for the choice

Preparation and material requirements

Detailed procedures, including safety measures

Citations

Provide work time for groups to proceed with implementation of their lab demonstration and to create their digital products of learning. Students may choose to use a still or video camera to capture important parts of the process to embed in their presentations.

Session 10: Teach OthersHave students present their digital products. Presentations should last from 5 to 10 minutes with another 5 minutes reserved for fielding questions from the group. Assess students as they present their projects using the slideshow rubric or a similar project rubric.

Session 11: Prove It
In preparation for assessment, students can learn more and hone their skills using the Chemical Reactions* simulation. Ask students to write answers to the following questions, which were posed at the start of this unit of study:

What is a chemical reaction?

How does chemical change occur?

How can you tell if a change is chemical or physical?

Administer the reaction quiz to test students' skills in recognizing reaction patterns and predicting the products of a chemical reaction. A key is provided.

Note: The unit Composting: Why Bother? is a good companion to this unit in which to explore chemical reactions as they pertain to society’s waste management procedures.

Prerequisite Skills

Prior science courses involving discrete experiments

Differentiated Instruction

Special Needs Student

Design specific slideshow templates

Monitor progress with additional check-in dates and custom forms

Select a reaction type that best fits the student’s level

Select specific Web sites for research

Give the student extra time and individual instruction

Shorten lab assignments

Accept help from support personnel or volunteers

Reduce the number of concepts needed to master

Pair the student with a buddy

Gifted/Talented Student

Require the student to give more reaction type examples and compounds with formulas

Require the presentation to be more in-depth and use additional technology

Have the student study an independent topic or perform more complex experiments on a reaction type

Have the student be a “director” or “producer” of the final DVD that compiles and edits all presentations into one format